This chapter discusses the various organizational structures that have been implemented for spacecraft mission operations systems, and the significance of such structures to operations. It aims to investigate the basic organizational philosophies derived from functional analysis, defining key management and operational positions and their shifting strategies, for a typical mission control centre. The management structure of a mission operations programme can make or break the success of the mission. Organization, control and authority begin at the top and the perception of these to the working troops in the operational trenches can have a large effect on how well their job is performed. The Shuttle Imaging Radar (SIR)-An experience showed that it is the nature of Shuttle flights to require changes to operational schedules, and therefore several unconventional steps were taken with the SIR-B organization in order to facilitate quick re-planning. Like any other organization, operations organizations must function efficiently and cost-effectively.